A sunshade device that shades a vehicle window is required to pivotally bias a windup shaft in a used sate after being installed in a vehicle such that a windup device has a windup force for winding up a sunshade. Accordingly, in a case of installing the sunshade device to a vehicle, the windup shaft and a bearing portion thereof are rotated relative to each other by a predetermined amount, to thereby provide a biasing force to a biasing member disposed therebetween. However, the process efficiency is poor in the process of providing a biasing force to a biasing member each time a sunshade device is installed to a vehicle.
Therefore, there is the technology disclosed in Patent Document 1 as the technology of providing a biasing force to a biasing member before the installation of a sunshade device to a car body to maintain a biasing state. The invention of Patent Document 1 is configured to prevent the rotation of a bearing bush inserted into and fixed to an end of a windup shaft and the rotation of a bearing element provided so as to rotate relative to the bearing bush, to which the other end of a helical spring whose one end is fixed into the inside of the windup shaft is fixed, to thereby maintain a biasing state of the helical spring. More specifically, arc-shaped anti-rotation ratchets formed in the bearing element so as to surround an outer periphery of the bearing bush are engaged with detent pockets formed on the outer periphery (collar) of the bearing bush, with the tips of the anti-rotation ratchets elastically deforming toward an inside in a radial direction, to thereby prevent the windup shaft from rotating relative to the bearing element.